It is known conventionally that many thiadiazine compounds have physiological activities; therefore they attract interest in the fields of medicine and agricultural chemicals. It is reported, for example, that some thiadiazine compounds have excellent pharmacological effects on inflammatory maladies and cardiopathies, and thiadiazine compounds have been recently developed as new type of vermin controller, such as buprofegin, that has a substituted amino group at 2-position of thiadiazine ring, and nematode controllers. However, the history of development of 1,3,5-thiadiazine compounds is short and synthesis examples are few, many of which involve complex steps and use expensive raw materials.